This invention relates to liquid crystal displays (LCDs), and more particularly to an auto mode detection circuit in LCDs which detects a vertical synchronous signal provided to a liquid crystal display module (LCM) and selects the operation mode of LCDs with the detection result.
Recently, any one of a data enable signal DE not containing synchronous signal or a data enable signal DE+SYNC containing synchronous signal is provided to a LCM according to computer manufacturers. In the prior, it has been to difficult to manually select the operation mode of a LCM using an external jumper according to the mode of the input signal which is received from a personal computer. Besides, although it manually changes the mode by using an external jumper, because there is a case that a controller of a LCM does not operate, the driving circuit of a LCM should be changed. Therefore, if it corresponds to PC manufacturers which provides the different signals to a LCM, it should supplement the function for selecting the desired mode in a controller according to the input signal.